Rename discardFramebufferEXT to discardBackbufferCHROMIUM to avoid collision with real discardFramebufferEXT

Calling the (real) discardFramebufferEXT in the compositor is a performance win, at least on tilers. However
currently it can't be called because we alias the name for a different API that controls backbuffer
allocation, which I don't want to change.  This renames the code to make backbuffer control a completely
separate API so I can pipe GL_EXT_discard_framebuffer in fully as a follow-up.

Depends on https://bugs.webkit.org/show_bug.cgi?id=104316

BUG=


Review URL: https://chromiumcodereview.appspot.com/11474014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@171908 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 47 insertions, 48 deletions

diff --git a/cc/gl_renderer.cc b/cc/gl_renderer.cc
index e625362..e9a76c1 100644
--- a/cc/gl_renderer.cc
+++ b/cc/gl_renderer.cc
@@ -74,8 +74,8 @@ GLRenderer::GLRenderer(RendererClient* client, ResourceProvider* resourceProvide
     , m_sharedGeometryQuad(gfx::RectF(-0.5f, -0.5f, 1.0f, 1.0f))
     , m_context(resourceProvider->graphicsContext3D())
     , m_isViewportChanged(false)
-    , m_isFramebufferDiscarded(false)
-    , m_discardFramebufferWhenNotVisible(false)
+    , m_isBackbufferDiscarded(false)
+    , m_discardBackbufferWhenNotVisible(false)
     , m_isUsingBindUniform(false)
     , m_visible(true)
     , m_isScissorEnabled(false)
@@ -119,7 +119,7 @@ bool GLRenderer::initialize()
     if (m_capabilities.usingGpuMemoryManager)
         m_context->setMemoryAllocationChangedCallbackCHROMIUM(this);
 
-    m_capabilities.usingDiscardFramebuffer = extensions.count("GL_CHROMIUM_discard_framebuffer");
+    m_capabilities.usingDiscardBackbuffer = extensions.count("GL_CHROMIUM_discard_backbuffer");
 
     m_capabilities.usingEglImage = extensions.count("GL_OES_EGL_image_external");
 
@@ -188,7 +188,7 @@ void GLRenderer::sendManagedMemoryStats(size_t bytesVisible, size_t bytesVisible
     stats.bytesVisible = bytesVisible;
     stats.bytesVisibleAndNearby = bytesVisibleAndNearby;
     stats.bytesAllocated = bytesAllocated;
-    stats.backbufferRequested = !m_isFramebufferDiscarded;
+    stats.backbufferRequested = !m_isBackbufferDiscarded;
     m_context->sendManagedMemoryStatsCHROMIUM(&stats);
 }
 
@@ -218,8 +218,8 @@ void GLRenderer::clearFramebuffer(DrawingFrame& frame)
 
 void GLRenderer::beginDrawingFrame(DrawingFrame& frame)
 {
-    // FIXME: Remove this once framebuffer is automatically recreated on first use
-    ensureFramebuffer();
+    // FIXME: Remove this once backbuffer is automatically recreated on first use
+    ensureBackbuffer();
 
     if (viewportSize().IsEmpty())
         return;
@@ -1242,7 +1242,7 @@ void GLRenderer::finish()
 bool GLRenderer::swapBuffers()
 {
     DCHECK(m_visible);
-    DCHECK(!m_isFramebufferDiscarded);
+    DCHECK(!m_isBackbufferDiscarded);
 
     TRACE_EVENT0("cc", "GLRenderer::swapBuffers");
     // We're done! Time to swapbuffers!
@@ -1286,11 +1286,11 @@ void GLRenderer::onMemoryAllocationChanged(WebGraphicsMemoryAllocation allocatio
             m_client->setManagedMemoryPolicy(policy);
     }
 
-    bool oldDiscardFramebufferWhenNotVisible = m_discardFramebufferWhenNotVisible;
-    m_discardFramebufferWhenNotVisible = !allocation.suggestHaveBackbuffer;
+    bool oldDiscardBackbufferWhenNotVisible = m_discardBackbufferWhenNotVisible;
+    m_discardBackbufferWhenNotVisible = !allocation.suggestHaveBackbuffer;
     enforceMemoryPolicy();
     if (allocation.enforceButDoNotKeepAsPolicy)
-        m_discardFramebufferWhenNotVisible = oldDiscardFramebufferWhenNotVisible;
+        m_discardBackbufferWhenNotVisible = oldDiscardBackbufferWhenNotVisible;
 }
 
 int GLRenderer::priorityCutoffValue(WebKit::WebGraphicsMemoryAllocation::PriorityCutoff priorityCutoff)
@@ -1314,38 +1314,37 @@ void GLRenderer::enforceMemoryPolicy()
     if (!m_visible) {
         TRACE_EVENT0("cc", "GLRenderer::enforceMemoryPolicy dropping resources");
         releaseRenderPassTextures();
-        if (m_discardFramebufferWhenNotVisible)
-            discardFramebuffer();
+        if (m_discardBackbufferWhenNotVisible)
+            discardBackbuffer();
         GLC(m_context, m_context->flush());
     }
 }
 
-void GLRenderer::discardFramebuffer()
+void GLRenderer::discardBackbuffer()
 {
-    if (m_isFramebufferDiscarded)
+    if (m_isBackbufferDiscarded)
         return;
 
-    if (!m_capabilities.usingDiscardFramebuffer)
+    if (!m_capabilities.usingDiscardBackbuffer)
         return;
 
-    // FIXME: Update attachments argument to appropriate values once they are no longer ignored.
-    m_context->discardFramebufferEXT(GL_TEXTURE_2D, 0, 0);
-    m_isFramebufferDiscarded = true;
+    m_context->discardBackbufferCHROMIUM();
+    m_isBackbufferDiscarded = true;
 
     // Damage tracker needs a full reset every time framebuffer is discarded.
     m_client->setFullRootLayerDamage();
 }
 
-void GLRenderer::ensureFramebuffer()
+void GLRenderer::ensureBackbuffer()
 {
-    if (!m_isFramebufferDiscarded)
+    if (!m_isBackbufferDiscarded)
         return;
 
-    if (!m_capabilities.usingDiscardFramebuffer)
+    if (!m_capabilities.usingDiscardBackbuffer)
         return;
 
-    m_context->ensureFramebufferCHROMIUM();
-    m_isFramebufferDiscarded = false;
+    m_context->ensureBackbufferCHROMIUM();
+    m_isBackbufferDiscarded = false;
 }
 
 void GLRenderer::onContextLost()
diff --git a/cc/gl_renderer.h b/cc/gl_renderer.h
index 653b4ac..4cfdfc0 100644
--- a/cc/gl_renderer.h
+++ b/cc/gl_renderer.h
@@ -68,7 +68,7 @@ protected:
 
     static void debugGLCall(WebKit::WebGraphicsContext3D*, const char* command, const char* file, int line);
 
-    bool isFramebufferDiscarded() const { return m_isFramebufferDiscarded; }
+    bool isBackbufferDiscarded() const { return m_isBackbufferDiscarded; }
     bool initialize();
 
     const gfx::QuadF& sharedGeometryQuad() const { return m_sharedGeometryQuad; }
@@ -130,8 +130,8 @@ private:
 
     // WebKit::WebGraphicsContext3D::WebGraphicsMemoryAllocationChangedCallbackCHROMIUM implementation.
     virtual void onMemoryAllocationChanged(WebKit::WebGraphicsMemoryAllocation) OVERRIDE;
-    void discardFramebuffer();
-    void ensureFramebuffer();
+    void discardBackbuffer();
+    void ensureBackbuffer();
     void enforceMemoryPolicy();
 
     // WebGraphicsContext3D::WebGraphicsContextLostCallback implementation.
@@ -222,8 +222,8 @@ private:
     gfx::Rect m_swapBufferRect;
     gfx::Rect m_scissorRect;
     bool m_isViewportChanged;
-    bool m_isFramebufferDiscarded;
-    bool m_discardFramebufferWhenNotVisible;
+    bool m_isBackbufferDiscarded;
+    bool m_discardBackbufferWhenNotVisible;
     bool m_isUsingBindUniform;
     bool m_visible;
     bool m_isScissorEnabled;
diff --git a/cc/gl_renderer_unittest.cc b/cc/gl_renderer_unittest.cc
index e4dcc54..48922e3 100644
--- a/cc/gl_renderer_unittest.cc
+++ b/cc/gl_renderer_unittest.cc
@@ -40,7 +40,7 @@ public:
     virtual WebString getString(WebKit::WGC3Denum name)
     {
         if (name == GL_EXTENSIONS)
-            return WebString("GL_CHROMIUM_set_visibility GL_CHROMIUM_gpu_memory_manager GL_CHROMIUM_discard_framebuffer");
+            return WebString("GL_CHROMIUM_set_visibility GL_CHROMIUM_gpu_memory_manager GL_CHROMIUM_discard_backbuffer");
         return WebString();
     }
 
@@ -112,7 +112,7 @@ public:
 
     // Changing visibility to public.
     using GLRenderer::initialize;
-    using GLRenderer::isFramebufferDiscarded;
+    using GLRenderer::isBackbufferDiscarded;
     using GLRenderer::drawQuad;
     using GLRenderer::beginDrawingFrame;
     using GLRenderer::finishDrawingQuadList;
@@ -150,20 +150,20 @@ protected:
     FakeRendererGL m_renderer;
 };
 
-// Test GLRenderer discardFramebuffer functionality:
+// Test GLRenderer discardBackbuffer functionality:
 // Suggest recreating framebuffer when one already exists.
 // Expected: it does nothing.
 TEST_F(GLRendererTest, SuggestBackbufferYesWhenItAlreadyExistsShouldDoNothing)
 {
     context()->setMemoryAllocation(m_suggestHaveBackbufferYes);
     EXPECT_EQ(0, m_mockClient.setFullRootLayerDamageCount());
-    EXPECT_FALSE(m_renderer.isFramebufferDiscarded());
+    EXPECT_FALSE(m_renderer.isBackbufferDiscarded());
 
     swapBuffers();
     EXPECT_EQ(1, context()->frameCount());
 }
 
-// Test GLRenderer discardFramebuffer functionality:
+// Test GLRenderer discardBackbuffer functionality:
 // Suggest discarding framebuffer when one exists and the renderer is not visible.
 // Expected: it is discarded and damage tracker is reset.
 TEST_F(GLRendererTest, SuggestBackbufferNoShouldDiscardBackbufferAndDamageRootLayerWhileNotVisible)
@@ -171,10 +171,10 @@ TEST_F(GLRendererTest, SuggestBackbufferNoShouldDiscardBackbufferAndDamageRootLa
     m_renderer.setVisible(false);
     context()->setMemoryAllocation(m_suggestHaveBackbufferNo);
     EXPECT_EQ(1, m_mockClient.setFullRootLayerDamageCount());
-    EXPECT_TRUE(m_renderer.isFramebufferDiscarded());
+    EXPECT_TRUE(m_renderer.isBackbufferDiscarded());
 }
 
-// Test GLRenderer discardFramebuffer functionality:
+// Test GLRenderer discardBackbuffer functionality:
 // Suggest discarding framebuffer when one exists and the renderer is visible.
 // Expected: the allocation is ignored.
 TEST_F(GLRendererTest, SuggestBackbufferNoDoNothingWhenVisible)
@@ -182,11 +182,11 @@ TEST_F(GLRendererTest, SuggestBackbufferNoDoNothingWhenVisible)
     m_renderer.setVisible(true);
     context()->setMemoryAllocation(m_suggestHaveBackbufferNo);
     EXPECT_EQ(0, m_mockClient.setFullRootLayerDamageCount());
-    EXPECT_FALSE(m_renderer.isFramebufferDiscarded());
+    EXPECT_FALSE(m_renderer.isBackbufferDiscarded());
 }
 
 
-// Test GLRenderer discardFramebuffer functionality:
+// Test GLRenderer discardBackbuffer functionality:
 // Suggest discarding framebuffer when one does not exist.
 // Expected: it does nothing.
 TEST_F(GLRendererTest, SuggestBackbufferNoWhenItDoesntExistShouldDoNothing)
@@ -194,26 +194,26 @@ TEST_F(GLRendererTest, SuggestBackbufferNoWhenItDoesntExistShouldDoNothing)
     m_renderer.setVisible(false);
     context()->setMemoryAllocation(m_suggestHaveBackbufferNo);
     EXPECT_EQ(1, m_mockClient.setFullRootLayerDamageCount());
-    EXPECT_TRUE(m_renderer.isFramebufferDiscarded());
+    EXPECT_TRUE(m_renderer.isBackbufferDiscarded());
 
     context()->setMemoryAllocation(m_suggestHaveBackbufferNo);
     EXPECT_EQ(1, m_mockClient.setFullRootLayerDamageCount());
-    EXPECT_TRUE(m_renderer.isFramebufferDiscarded());
+    EXPECT_TRUE(m_renderer.isBackbufferDiscarded());
 }
 
-// Test GLRenderer discardFramebuffer functionality:
+// Test GLRenderer discardBackbuffer functionality:
 // Begin drawing a frame while a framebuffer is discarded.
 // Expected: will recreate framebuffer.
 TEST_F(GLRendererTest, DiscardedBackbufferIsRecreatedForScopeDuration)
 {
     m_renderer.setVisible(false);
     context()->setMemoryAllocation(m_suggestHaveBackbufferNo);
-    EXPECT_TRUE(m_renderer.isFramebufferDiscarded());
+    EXPECT_TRUE(m_renderer.isBackbufferDiscarded());
     EXPECT_EQ(1, m_mockClient.setFullRootLayerDamageCount());
 
     m_renderer.setVisible(true);
     m_renderer.drawFrame(m_mockClient.renderPassesInDrawOrder(), m_mockClient.renderPasses());
-    EXPECT_FALSE(m_renderer.isFramebufferDiscarded());
+    EXPECT_FALSE(m_renderer.isBackbufferDiscarded());
 
     swapBuffers();
     EXPECT_EQ(1, context()->frameCount());
@@ -223,15 +223,15 @@ TEST_F(GLRendererTest, FramebufferDiscardedAfterReadbackWhenNotVisible)
 {
     m_renderer.setVisible(false);
     context()->setMemoryAllocation(m_suggestHaveBackbufferNo);
-    EXPECT_TRUE(m_renderer.isFramebufferDiscarded());
+    EXPECT_TRUE(m_renderer.isBackbufferDiscarded());
     EXPECT_EQ(1, m_mockClient.setFullRootLayerDamageCount());
 
     char pixels[4];
     m_renderer.drawFrame(m_mockClient.renderPassesInDrawOrder(), m_mockClient.renderPasses());
-    EXPECT_FALSE(m_renderer.isFramebufferDiscarded());
+    EXPECT_FALSE(m_renderer.isBackbufferDiscarded());
 
     m_renderer.getFramebufferPixels(pixels, gfx::Rect(0, 0, 1, 1));
-    EXPECT_TRUE(m_renderer.isFramebufferDiscarded());
+    EXPECT_TRUE(m_renderer.isBackbufferDiscarded());
     EXPECT_EQ(2, m_mockClient.setFullRootLayerDamageCount());
 }
 
@@ -457,7 +457,7 @@ public:
     virtual WebString getString(WebKit::WGC3Denum name)
     {
         if (name == GL_EXTENSIONS)
-            return WebString("GL_CHROMIUM_set_visibility GL_CHROMIUM_gpu_memory_manager GL_CHROMIUM_discard_framebuffer");
+            return WebString("GL_CHROMIUM_set_visibility GL_CHROMIUM_gpu_memory_manager GL_CHROMIUM_discard_backbuffer");
         return WebString();
     }
 
diff --git a/cc/layer_tree_host.cc b/cc/layer_tree_host.cc
index 00a7b68..948e0b9 100644
--- a/cc/layer_tree_host.cc
+++ b/cc/layer_tree_host.cc
@@ -152,7 +152,7 @@ RendererCapabilities::RendererCapabilities()
     , usingSetVisibility(false)
     , usingSwapCompleteCallback(false)
     , usingGpuMemoryManager(false)
-    , usingDiscardFramebuffer(false)
+    , usingDiscardBackbuffer(false)
     , usingEglImage(false)
     , allowPartialTextureUpdates(false)
     , maxTextureSize(0)
diff --git a/cc/layer_tree_host.h b/cc/layer_tree_host.h
index 21af798..3f6b9ba 100644
--- a/cc/layer_tree_host.h
+++ b/cc/layer_tree_host.h
@@ -117,7 +117,7 @@ struct CC_EXPORT RendererCapabilities {
     bool usingSetVisibility;
     bool usingSwapCompleteCallback;
     bool usingGpuMemoryManager;
-    bool usingDiscardFramebuffer;
+    bool usingDiscardBackbuffer;
     bool usingEglImage;
     bool allowPartialTextureUpdates;
     int maxTextureSize;