Bug 1542344 - fix API mismatches in ImageEncoder; r=mccr8

ImageEncoder::ExtractDataInternal takes a `const nsAString&` for its
options, but flattens it into a null-terminated `nsString` so callees
can take a `char16_t*`.  But nearly all of those callees eventually wind
up calling ImageEncoder::GetInputStream, which just constructs an
`nsDependentString` from the passed character pointer.

There's no reason to do all this extra work.  We can just pass the
original options reference all the way through the stack and avoid
needless conversions.

Differential Revision: https://phabricator.services.mozilla.com/D26353

--HG--
extra : moz-landing-system : lando

dom/base/ImageEncoder.cpp

@@ -285,11 +285,11 @@ nsresult ImageEncoder::ExtractDataAsync(
 nsresult ImageEncoder::GetInputStream(int32_t aWidth, int32_t aHeight,
                                       uint8_t* aImageBuffer, int32_t aFormat,
                                       imgIEncoder* aEncoder,
-                                      const char16_t* aEncoderOptions,
+                                      const nsAString& aEncoderOptions,
                                       nsIInputStream** aStream) {
   nsresult rv = aEncoder->InitFromData(aImageBuffer, aWidth * aHeight * 4,
                                        aWidth, aHeight, aWidth * 4, aFormat,
-                                       nsDependentString(aEncoderOptions));
+                                       aEncoderOptions);
   NS_ENSURE_SUCCESS(rv, rv);
 
   nsCOMPtr<imgIEncoder> encoder(aEncoder);
@@ -319,16 +319,14 @@ nsresult ImageEncoder::ExtractDataInternal(
 
     rv = ImageEncoder::GetInputStream(
         aSize.width, aSize.height, aImageBuffer, aFormat, aEncoder,
-        nsPromiseFlatString(aOptions).get(), getter_AddRefs(imgStream));
+        aOptions, getter_AddRefs(imgStream));
   } else if (aContext && !aUsePlaceholder) {
     NS_ConvertUTF16toUTF8 encoderType(aType);
-    rv = aContext->GetInputStream(encoderType.get(),
-                                  nsPromiseFlatString(aOptions).get(),
+    rv = aContext->GetInputStream(encoderType.get(), aOptions,
                                   getter_AddRefs(imgStream));
   } else if (aRenderer && !aUsePlaceholder) {
     NS_ConvertUTF16toUTF8 encoderType(aType);
-    rv = aRenderer->GetInputStream(encoderType.get(),
-                                   nsPromiseFlatString(aOptions).get(),
+    rv = aRenderer->GetInputStream(encoderType.get(), aOptions,
                                    getter_AddRefs(imgStream));
   } else if (aImage && !aUsePlaceholder) {
     // It is safe to convert PlanarYCbCr format from YUV to RGB off-main-thread.

dom/base/ImageEncoder.h

@@ -78,7 +78,7 @@ class ImageEncoder {
   static nsresult GetInputStream(int32_t aWidth, int32_t aHeight,
                                  uint8_t* aImageBuffer, int32_t aFormat,
                                  imgIEncoder* aEncoder,
-                                 const char16_t* aEncoderOptions,
+                                 const nsAString& aEncoderOptions,
                                  nsIInputStream** aStream);
 
  private:

dom/canvas/CanvasRenderingContext2D.cpp

@@ -1648,7 +1648,7 @@ nsString CanvasRenderingContext2D::GetHitRegion(
 
 NS_IMETHODIMP
 CanvasRenderingContext2D::GetInputStream(const char* aMimeType,
-                                         const char16_t* aEncoderOptions,
+                                         const nsAString& aEncoderOptions,
                                          nsIInputStream** aStream) {
   nsCString enccid("@mozilla.org/image/encoder;2?type=");
   enccid += aMimeType;

dom/canvas/CanvasRenderingContext2D.h

@@ -405,7 +405,7 @@ class CanvasRenderingContext2D final : public nsICanvasRenderingContextInternal,
       nsIDocShell* aShell, NotNull<gfx::DrawTarget*> aTarget) override;
 
   NS_IMETHOD GetInputStream(const char* aMimeType,
-                            const char16_t* aEncoderOptions,
+                            const nsAString& aEncoderOptions,
                             nsIInputStream** aStream) override;
 
   already_AddRefed<mozilla::gfx::SourceSurface> GetSurfaceSnapshot(

dom/canvas/ImageBitmapRenderingContext.cpp

@@ -139,7 +139,7 @@ mozilla::UniquePtr<uint8_t[]> ImageBitmapRenderingContext::GetImageBuffer(
 
 NS_IMETHODIMP
 ImageBitmapRenderingContext::GetInputStream(const char* aMimeType,
-                                            const char16_t* aEncoderOptions,
+                                            const nsAString& aEncoderOptions,
                                             nsIInputStream** aStream) {
   nsCString enccid("@mozilla.org/image/encoder;2?type=");
   enccid += aMimeType;

dom/canvas/ImageBitmapRenderingContext.h

@@ -62,7 +62,7 @@ class ImageBitmapRenderingContext final
   virtual mozilla::UniquePtr<uint8_t[]> GetImageBuffer(
       int32_t* aFormat) override;
   NS_IMETHOD GetInputStream(const char* aMimeType,
-                            const char16_t* aEncoderOptions,
+                            const nsAString& aEncoderOptions,
                             nsIInputStream** aStream) override;
 
   virtual already_AddRefed<mozilla::gfx::SourceSurface> GetSurfaceSnapshot(

dom/canvas/WebGLContext.cpp

@@ -1069,7 +1069,7 @@ UniquePtr<uint8_t[]> WebGLContext::GetImageBuffer(int32_t* out_format) {
 
 NS_IMETHODIMP
 WebGLContext::GetInputStream(const char* mimeType,
-                             const char16_t* encoderOptions,
+                             const nsAString& encoderOptions,
                              nsIInputStream** out_stream) {
   NS_ASSERTION(gl, "GetInputStream on invalid context?");
   if (!gl) return NS_ERROR_FAILURE;

dom/canvas/WebGLContext.h

@@ -369,7 +369,7 @@ class WebGLContext : public nsICanvasRenderingContextInternal,
 
   virtual UniquePtr<uint8_t[]> GetImageBuffer(int32_t* out_format) override;
   NS_IMETHOD GetInputStream(const char* mimeType,
-                            const char16_t* encoderOptions,
+                            const nsAString& encoderOptions,
                             nsIInputStream** out_stream) override;
 
   virtual already_AddRefed<mozilla::gfx::SourceSurface> GetSurfaceSnapshot(

dom/canvas/nsICanvasRenderingContextInternal.h

@@ -112,7 +112,7 @@ class nsICanvasRenderingContextInternal : public nsISupports,
   // is false, alpha will be discarded and the result will be the image
   // composited on black.
   NS_IMETHOD GetInputStream(const char* mimeType,
-                            const char16_t* encoderOptions,
+                            const nsAString& encoderOptions,
                             nsIInputStream** stream) = 0;
 
   // This gets an Azure SourceSurface for the canvas, this will be a snapshot

gfx/layers/AsyncCanvasRenderer.cpp

@@ -242,7 +242,7 @@ already_AddRefed<gfx::DataSourceSurface> AsyncCanvasRenderer::GetSurface() {
 }
 
 nsresult AsyncCanvasRenderer::GetInputStream(const char* aMimeType,
-                                             const char16_t* aEncoderOptions,
+                                             const nsAString& aEncoderOptions,
                                              nsIInputStream** aStream) {
   MOZ_ASSERT(NS_IsMainThread());
   RefPtr<gfx::DataSourceSurface> surface = GetSurface();

gfx/layers/AsyncCanvasRenderer.h

@@ -89,7 +89,7 @@ class AsyncCanvasRenderer final {
   // function called GetSurface implicitly and GetSurface handles only get
   // called in the main thread. So this function can be called in main thread.
   nsresult GetInputStream(const char* aMimeType,
-                          const char16_t* aEncoderOptions,
+                          const nsAString& aEncoderOptions,
                           nsIInputStream** aStream);
 
   gfx::IntSize GetSize() const { return gfx::IntSize(mWidth, mHeight); }

gfx/thebes/gfxUtils.cpp

@@ -1343,7 +1343,7 @@ void gfxUtils::CopyAsDataURI(DrawTarget* aDT) {
 nsresult gfxUtils::GetInputStream(gfx::DataSourceSurface* aSurface,
                                   bool aIsAlphaPremultiplied,
                                   const char* aMimeType,
-                                  const char16_t* aEncoderOptions,
+                                  const nsAString& aEncoderOptions,
                                   nsIInputStream** outStream) {
   nsCString enccid("@mozilla.org/image/encoder;2?type=");
   enccid += aMimeType;

gfx/thebes/gfxUtils.h

@@ -295,7 +295,7 @@ class gfxUtils {
   static nsresult GetInputStream(DataSourceSurface* aSurface,
                                  bool aIsAlphaPremultiplied,
                                  const char* aMimeType,
-                                 const char16_t* aEncoderOptions,
+                                 const nsAString& aEncoderOptions,
                                  nsIInputStream** outStream);
 
   static nsresult ThreadSafeGetFeatureStatus(