[devtools] Support different encodings for Page.CaptureScreenshot.

ui/snapshot/snapshot_mac.mm

Index: ui/snapshot/snapshot_mac.mm
diff --git a/ui/snapshot/snapshot_mac.mm b/ui/snapshot/snapshot_mac.mm
index 9761cb7f5086136f36de50109e04e7e0e92222eb..2c87e38889cfdc4ded160991582c1acfbb14af07 100644
--- a/ui/snapshot/snapshot_mac.mm
+++ b/ui/snapshot/snapshot_mac.mm
@@ -19,7 +19,9 @@ namespace ui {
 
 bool GrabViewSnapshot(gfx::NativeView view,
                       std::vector<unsigned char>* png_representation,
-                      const gfx::Rect& snapshot_bounds) {
+                      const gfx::Rect& snapshot_bounds,
+                      SnapshotEncoding encoding,
+                      SnapshotQuality quality) {
   NSWindow* window = [view window];
   NSScreen* screen = [[NSScreen screens] firstObject];
   gfx::Rect screen_bounds = gfx::Rect(NSRectToCGRect([screen frame]));
@@ -55,7 +57,23 @@ bool GrabViewSnapshot(gfx::NativeView view,
 
   base::scoped_nsobject<NSBitmapImageRep> rep(
       [[NSBitmapImageRep alloc] initWithCGImage:windowSnapshot]);
-  NSData* data = [rep representationUsingType:NSPNGFileType properties:@{}];
+  NSData* data;
+  float compression_factor = 0;
+  NSDictionary* options = nullptr;
+  switch (encoding) {
+    case SnapshotEncoding::PNG:
+      data = [rep representationUsingType:NSPNGFileType properties:@{}];
+      break;
+    case SnapshotEncoding::JPEG:
+      compression_factor = static_cast<float>(quality) / 100;
+      options = [NSDictionary
+          dictionaryWithObject:[NSNumber numberWithFloat:compression_factor]
+                        forKey:NSImageCompressionFactor];
+      data = [rep representationUsingType:NSJPEGFileType properties:options];
+      break;
+    default:
+      NOTREACHED();
+  }
   const unsigned char* buf = static_cast<const unsigned char*>([data bytes]);
   NSUInteger length = [data length];
   if (buf == NULL || length == 0)
@@ -69,11 +87,13 @@ bool GrabViewSnapshot(gfx::NativeView view,
 
 bool GrabWindowSnapshot(gfx::NativeWindow window,
                         std::vector<unsigned char>* png_representation,
-                        const gfx::Rect& snapshot_bounds) {
+                        const gfx::Rect& snapshot_bounds,
+                        SnapshotEncoding encoding,
+                        SnapshotQuality quality) {
   // Make sure to grab the "window frame" view so we get current tab +
   // tabstrip.
   return GrabViewSnapshot([[window contentView] superview], png_representation,
-      snapshot_bounds);
+                          snapshot_bounds, encoding, quality);
 }
 
 void GrabWindowSnapshotAndScaleAsync(
@@ -89,7 +109,9 @@ void GrabViewSnapshotAsync(
     gfx::NativeView view,
     const gfx::Rect& source_rect,
     scoped_refptr<base::TaskRunner> background_task_runner,
-    const GrabWindowSnapshotAsyncPNGCallback& callback) {
+    const GrabWindowSnapshotAsyncEncodedCallback& callback,
+    SnapshotEncoding encoding,
+    SnapshotQuality quality) {
   callback.Run(scoped_refptr<base::RefCountedBytes>());
 }
 
@@ -97,9 +119,12 @@ void GrabWindowSnapshotAsync(
     gfx::NativeWindow window,
     const gfx::Rect& source_rect,
     scoped_refptr<base::TaskRunner> background_task_runner,
-    const GrabWindowSnapshotAsyncPNGCallback& callback) {
+    const GrabWindowSnapshotAsyncEncodedCallback& callback,
+    SnapshotEncoding encoding,
+    SnapshotQuality quality) {
   return GrabViewSnapshotAsync([[window contentView] superview], source_rect,
-      background_task_runner, callback);
+                               background_task_runner, callback, encoding,
+                               quality);
 }
 
 }  // namespace ui