Bug 1707943 - Fix warnings and apply suggestions form static analysis, r=stransky

Some more small cleanups to stop the review bot from complaining in
patches touching these files.

Differential Revision: https://phabricator.services.mozilla.com/D113721

gfx/thebes/gfxPlatformGtk.cpp

@@ -413,7 +413,7 @@ gfxImageFormat gfxPlatformGtk::GetOffscreenFormat() {
 
 void gfxPlatformGtk::FontsPrefsChanged(const char* aPref) {
   // only checking for generic substitions, pass other changes up
-  if (strcmp(GFX_PREF_MAX_GENERIC_SUBSTITUTIONS, aPref)) {
+  if (strcmp(GFX_PREF_MAX_GENERIC_SUBSTITUTIONS, aPref) != 0) {
     gfxPlatform::FontsPrefsChanged(aPref);
     return;
   }
@@ -519,7 +519,7 @@ nsTArray<uint8_t> gfxPlatformGtk::GetPlatformCMSOutputProfileData() {
   }
 
   // Format documented in "VESA E-EDID Implementation Guide"
-  float gamma = (100 + retProperty[0x17]) / 100.0f;
+  float gamma = (100 + (float)retProperty[0x17]) / 100.0f;
 
   qcms_CIE_xyY whitePoint;
   whitePoint.x =
@@ -739,7 +739,7 @@ class GtkVsyncSource final : public VsyncSource {
         // until the parity of the counter value changes.
         unsigned int nextSync = syncCounter + 1;
         int status;
-        if ((status = gl::sGLXLibrary.fWaitVideoSync(2, nextSync % 2,
+        if ((status = gl::sGLXLibrary.fWaitVideoSync(2, (int)nextSync % 2,
                                                      &syncCounter)) != 0) {
           gfxWarningOnce() << "glXWaitVideoSync returned " << status;
           useSoftware = true;
@@ -755,7 +755,7 @@ class GtkVsyncSource final : public VsyncSource {
           double remaining =
               (1000.f / 60.f) - (TimeStamp::Now() - lastVsync).ToMilliseconds();
           if (remaining > 0) {
-            PlatformThread::Sleep(remaining);
+            PlatformThread::Sleep((int)remaining);
           }
         }
 

widget/GfxInfoX11.cpp

@@ -231,7 +231,7 @@ void GfxInfo::GetData() {
 
   // only useful for Linux kernel version check for FGLRX driver.
   // assumes X client == X server, which is sad.
-  struct utsname unameobj;
+  struct utsname unameobj {};
   if (uname(&unameobj) >= 0) {
     mOS.Assign(unameobj.sysname);
     mOSRelease.Assign(unameobj.release);
@@ -338,7 +338,7 @@ void GfxInfo::GetData() {
     while (loc != kNotFound) {
       int isDefault = 0;
       nsCString line(screenInfo.get() + start, loc - start);
-      ScreenInfo info;
+      ScreenInfo info{};
       if (sscanf(line.get(), "%ux%u:%u", &info.mWidth, &info.mHeight,
                  &isDefault) == 3) {
         info.mIsDefault = isDefault != 0;

widget/gtk/MozContainerWayland.cpp

@@ -569,8 +569,8 @@ struct wl_egl_window* moz_container_wayland_get_egl_window(
   if (!wl_container->eglwindow) {
     GdkWindow* window = gtk_widget_get_window(GTK_WIDGET(container));
     wl_container->eglwindow = wl_egl_window_create(
-        wl_container->surface, round(gdk_window_get_width(window) * scale),
-        round(gdk_window_get_height(window) * scale));
+        wl_container->surface, (int)round(gdk_window_get_width(window) * scale),
+        (int)round(gdk_window_get_height(window) * scale));
 
     LOGWAYLAND(("%s [%p] created eglwindow %p\n", __FUNCTION__,
                 (void*)container, (void*)wl_container->eglwindow));
@@ -579,7 +579,7 @@ struct wl_egl_window* moz_container_wayland_get_egl_window(
 }
 
 gboolean moz_container_wayland_has_egl_window(MozContainer* container) {
-  return container->wl_container.eglwindow ? true : false;
+  return container->wl_container.eglwindow != nullptr;
 }
 
 gboolean moz_container_wayland_surface_needs_clear(MozContainer* container) {